Another timeslip later, she's watching him suck on an oxygen mask. Which he does not offer to share. When he's done, he says he doesn't know how much Walter has told her, or what he even remembers. Olivia says he told her what they did to her. "How you conducted drug trials on young children." Bell guiltily says they weren't trying to hurt anyone, but Olivia doesn't let him off the hook. "I've met some of the others. To say that they are permanently damaged would be an understatement." Bell laments the "unintended consequences," but he can see she isn't one of them. "In fact, you're just coming into your ability." Whatever that means. This must have been an easy scene to write; rather than having to come up with organic shifts between one conversational topic and another, you can just drop in another timeslip effect when it's time to move on. And that's what happens now.
At the end of this shift, Bell is standing on the other side of the room from where he was, but Olivia acts like nothing happened as she turns to where he is now, like a slow-reacting anchorperson trying to follow which camera is live. Bell is in the middle of telling her that a war is coming, as per his and Walter's predictions back in the day. "And we knew we had to prepare a guardian. Someone to watch the gate." Bell digresses a bit about "this side and yours," adding that he can't go back yet, or maybe ever, and very few people have ever crossed over safely from Olivia's side. However, Bell tells her that those from his side have had more success, as we already know. He says they've "developed hybrids, part organic tissue, part machine, that can do things that humans can't." He says they can change shapes. "Over here, they call them the First Wave." And apparently they've been shuttling back and forth for decades, ever since the time of their original experiments on Rebecca Kibner, if not before. Bell tells Olivia that he knows it's "difficult to grasp," but she assures him she gets it. "I don't trust you, Dr. Bell," she says, making a big deal of refusing to call him William or Willem, "or whatever cutesy name you think might appeal to my childhood instincts." As though she still had any. As the screen washes yellow and then back, she tells him about all the crap Massive Dynamic has been pulling back in her world, "To say nothing of the fact that you just yanked me into a parallel universe to warn me about an interdimensional war that I believe you are responsible for starting." She demands the truth. Bell just says, "The truth will come out. It always does." Especially on TV. But not before someone on the writing staff has figured out what it is. Calling her Livvie, he insists, "I have a unique perspective shaped by having lived in two worlds. I know the difference a wrong choice can make. Or a right one." Is he referring to his singing career? "For example, this building is still standing because different choices were made." Yeah, seems to me like it only would have taken one or two, but we don't need to get into that. He assures her that she should consider him an ally, and after another timeslip, he's telling her, "A storm is coming. Perhaps the last and worst storm of all. And when it is over, I fear there will be little left of our world." Wait, whose world, now? He says the shapeshifters on Olivia's side are looking for someone to open the door between the worlds. "If they find him, there will be no stopping them. And that is why you must find him first." Olivia's like, Who now? "You are The One, Olivia," Bell tells her. "Of all the children Walter and I prepared, you were the strongest. You were always the strongest." How lucky that she's the one we've been following all this time, then.